Berbatov held talks with Spurs sporting director Damien Comolli on Monday in a bid to clarify his position at the club.
Berbatov senior told the Mirror: "My son doesn't feel happy at Tottenham any more. He wants to leave."
The striker's father and the player's agent, Emil Dantchev, then left Sofia to fly to London for more talks with Spurs hierarchy.
Sources close to the striker added: "Dimitar is telling everybody that he doesn't want to stay and would like to leave in January.
"He feels that he made a mistake in the summer by not asking the club to sell him when Manchester United were interested."